CVE-2017-6721 Explained : Impact and Mitigation

Cisco Wide Area Application Services (WAAS) is affected by a vulnerability that allows unauthorized attackers to cause a denial of service (DoS) by exploiting the way fragmented TCP packets are handled during ingress processing.

Understanding CVE-2017-6721

This CVE identifies a flaw in Cisco WAAS that could lead to a DoS situation.

What is CVE-2017-6721?

The vulnerability in Cisco WAAS could be exploited by attackers to trigger an unexpected restart of the WAASNET process, resulting in a DoS condition.

The Impact of CVE-2017-6721

The vulnerability could potentially lead to a denial of service (DoS) situation by causing the WAASNET process to restart unexpectedly.

Technical Details of CVE-2017-6721

Cisco WAAS vulnerability details and affected systems.

Vulnerability Description

The flaw in Cisco WAAS allows unauthorized attackers to exploit fragmented TCP packets during ingress processing, leading to a DoS scenario.

Affected Systems and Versions

Affected Versions: 6.3(1)
Resolved Versions: 6.3(0.143), 6.2(3c)6, 6.2(3.22)

Exploitation Mechanism

Attackers can exploit the way fragmented TCP packets are handled to cause the unexpected restart of the WAASNET process, resulting in a DoS.

Mitigation and Prevention

Steps to mitigate and prevent the CVE-2017-6721 vulnerability.

Immediate Steps to Take

Apply the necessary patches provided by Cisco to address the vulnerability.
Monitor network traffic for any suspicious activities that could indicate an ongoing attack.

Long-Term Security Practices

Regularly update and patch Cisco WAAS to prevent known vulnerabilities.
Implement network segmentation and access controls to limit the impact of potential attacks.

Patching and Updates

Ensure that Cisco WAAS is updated to the fixed versions (6.3(0.143), 6.2(3c)6, 6.2(3.22) to mitigate the vulnerability.